TRENTON, N.J. — A state judge refused Thursday to delay the start of same-sex marriage in New Jersey until a legal appeal can be settled. But the administration of Republican Gov. Chris Christie immediately sought and was granted a request to file an emergency challenge to the decision. If the administration does not prevail, the state must grant marriage licenses for same-sex couples starting Oct. 21.

“Granting a stay would simply allow the state to continue to violate the equal protection rights of New Jersey same-sex couples, which can hardly be considered a public interest,” Judge Mary Jacobson ruled Thursday, refusing to put on hold her order issued last month.

The administration issued a statement saying only that it was now asking the state appeals court to overturn her ruling while it also continues to ask the state Supreme Court to take up the matter on an expedited basis as well.

Christie, a possible candidate for president in 2016 who is now running for a second term as governor, has said gay marriage should be made legal in New Jersey only if voters agree at a referendum, though none is scheduled.